This is an application for partial funding of a meeting that is the fourth in a series of International Lymphokine Workshops. This year's theme will be "Molecular Structure and Mechanism of Action of Lymphokines". The Workshop will be held October 17-21, 1984 at Schloss Elmau in Bavaria, Germany, which will provide a relatively "closed" environment in an isolated yet accessible location. The organizers of this event are Drs. Cohen, Pierce, Schimpl and Sorg, assisted by a Scientific Advisory Committee with international representation. It is anticipated that, as in the past, this meeting will help achieve new collective insights into the relationship of lymphokines to other regulatory macromolecules. This year special attention will be devoted to the mechanism of action of the various lymphokines, as well as their structure-function relationships. In addition, this meeting will foster discussions leading to unifying concepts regarding momenclature, standardization of assays, etc. Perhaps of greatest importance, the meeting should help to define and clarify new problems, directions, and approaches for both basic scientific investigations and possible therapeutic applications.